1. Field of the Invention
The present invention relates generally to the compression, cataloging and viewing of full motion videos and, more particularly, to the processing of compressed video data.
2. Description of Related Art
The infrastructure and process required to create and operate a video archive in the digital domain are well known in the broadcast video industry. The archiving process generally begins by digitizing and compressing the analog video using MPEG-1 or MPEG-2 compression, then moving the compressed video file to a long term storage. To preserve the contribution quality of the video, broadcasters generally select a high compressed bitrate (i.e., 15-40 Mbps), which allows the original video to be recovered with relatively high fidelity in spite of the lossiness of the MPEG compression scheme.
The high bitrate of the compressed video, however, presents considerable problems to the broadcaster""s local area network and computer workstation infrastructure, when the video must be distributed for viewing and post-production work. The high network bandwidth and the amount of time required to transfer the assets throughout the plant places an upper limit on the number of concurrent transfers and severely constrains productivity. In response to this bandwidth problem, broadcasters create an additional copy of the video at a much lower compressed bitrate (i.e., 1.5-4 Mbps). This low bitrate file, referred to as a xe2x80x98proxyxe2x80x99 or xe2x80x98browsexe2x80x99 file, enables users to quickly download the video or to view it directly on computer monitors by utilizing a streaming video server. To facilitate the viewing of video assets outside the local area network, a second proxy file is often encoded at a very low bitrate (56-1000 Kbps), for streaming over low speed terrestrial lines.
After ingestion of the video, the next step in the archiving process is to create an entry for the video in the video library catalog. This entry contains metadata, which is information pertinent to the video. The contents and format of a video catalog record, normally broadcaster unique, facilitate the search and retrieval of video clips within the broadcaster""s video library. Presently, there are commercially available video catalog applications (catalogers) that will automatically extract from an MPEG-1 or MPEG-2 video file metadata, such as closed caption text and the text of the actual audio program, obtained via speech recognition technology. Catalogers further extract metadata from the video by performing scene change analysis and creating a bitmap of the first frame after each cut or major scene transition. These bitmaps, referred to individually as a xe2x80x98thumbnailxe2x80x99 or collectively as a storyboard, are considered essential metadata because they enable the end user to determine very quickly the video content. Absent the storyboard, the end user is forced to view the video or, at a minimum, fast forward through a video to find the desired video segment.
Because of subtle scene transitions and video effects, the cataloger does not always capture all desired scene changes. Conversely, at times the scene change detection is too sensitive creating an excessive number of unwanted thumbnails. To remedy this, the MPEG player and metadata viewer applications used in parallel allow an end user to add or delete thumbnails from the storyboard. An xe2x80x98Add Thumbnailxe2x80x99 button on the MPEG player allows a user to select any frame in the video for thumbnail creation.
Should the storyboard metadata be lost due to user error, storyboard file or database corruption, or system failure, the video catalog librarian must re-invoke the cataloger application to recreate the storyboard. This is undesirable from an archive operations perspective because a cataloging workstation is an expensive, limited resource that is dedicated to ingest operations. Worst yet, the lost storyboard may have required considerable manual processing to select the chosen thumbnails. A method for automatically recreating a lost storyboard would considerably enhance cataloging operations.
Managing rights to video content is another very important issue for broadcasters. When broadcasters obtain or ingest material for which they have no rights, the content owner is contacted and full or limited rights to broadcast are obtained through negotiation. Frequently, the broadcaster requests rights to only one or more specific segments of the video clip because the remaining video is low-quality, irrelevant or off-topic. The terms and conditions of the rights agreement are stored as part of the catalog record. In order to ensure the restricted portion of the video is never aired or distributed, an video archive librarian edits the video clip to excise the restricted content.
A disadvantage of this business practice is that the content deleted from the clip may someday become valuable, in which case the broadcaster would then be willing to pay for the right to broadcast it. However, since the desired content is no longer in the video library, it is not searchable and the content owner must be contacted to search for and supply the video. If the broadcaster had a reliable, enforceable method for rights management and content control, program material for which rights have not yet been requested or negotiated could be stored in the video library without fear of inadvertent use. Presently available techniques of maintaining rights status in a catalog record or in a traffic and scheduling database do not provide adequate system control to prevent unauthorized use of restricted content.
Therefore, there is a need for a system and method for inserting storyboard and rights metadata information, for automatic recreation of a lost storyboard, and for an adequate prevention of unauthorized use of restricted video content which is saved in the video library.
The foregoing and other objects, features, and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments which makes reference to several drawing figures.
One preferred embodiment of the present invention is a method for storyboard thumbnail and video rights metadata insertion, for preventing unauthorized use of restricted video frames of a previously encoded MPEG video file. The method has a step for inserting video rights metadata in the timecode packet of the affected video frame of the MPEG video file; a step for inserting thumbnail status metadata in the timecode packet of the selected video storyboard thumbnail frame of the MPEG video file, allowing automatic recreation of a storyboard file from the MPEG video file; a step for updating the video rights metadata in a video catalog record, and in the timecode packet of the affected video frame of the MPEG video file; and a step for updating the thumbnail status metadata in a video catalog record, and in the timecode packet of the selected video storyboard thumbnail frame of the MPEG video file, thereby preserving the MPEG compliance and compressed audio/video data of the MPEG video file, while maintaining the MPEG video file""s original frame presentation timing.
The method creates and uses a custom-built GUI for creating a video rights edit decision list (EDL) of restricted frames, useable during a video file editing session for preventing unauthorized use of restricted video frames, and uses the video rights EDL for inserting or updating the video rights metadata flags of the affected video frame of the MPEG video file. The method locates the timecode packet of the affected video frame of the MPEG video file randomly by binary search, using the video frame""s nearest GOP header byte offset obtained through a GOP offset table lookup. The video rights metadata is selected from a group of full rights, limited rights, no rights, or expired rights.
Another preferred embodiment of the present invention is an apparatus implementing the abovementioned method embodiment of the present invention.
Yet another preferred embodiment of the present invention is a program storage device readable by a computer tangibly embodying a program of instructions executable by the computer to perform method steps of the above-mentioned method embodiment of the present invention.